Probiotic bacteria are defined as live microorganisms which when administered in adequate amounts beneficially affect the host. Lactobacilli and bifidobacteria are the most frequently used bacteria in probiotic products. These bacteria are generally safe, as are probiotics based on these organisms. The lack of pathogenicity extends across all age groups and to immunocompromised individuals. Intake of different probiotic bacteria has been shown to have clinical benefits in various physiologic or pathologic situations. The most clear cut effects have been shown in diarrhea caused by antibiotic therapy or rotavirus infection. There are also studies showing positive clinical effects in inflammatory bowel diseases, atopic dermatitis and hypercholesterolemia after intake of probiotic bacteria. The mechanism, by which probiotic bacteria contribute to these clinical improvements are not clear. In vitro human, as well as both in vivo and in vitro animal studies have shown that different species of lactobacilli affects the innate and acquired immune system in many different ways.
Clinical studies have mainly shown stimulation of the innate cellular immune system and enhancement of humoral immune responses to natural infections and systemic or oral immunisation. Regarding effects of the innate immune system, increased phagocytic activity of polymorphonuclear cells (PMN) and increased NK cell tumor killing activity have been reported. To our knowledge, there are no clinical studies showing effects on the specific cellular immune system after intake of probiotic bacteria.
In the present application the effects on the innate and acquired immune system following daily intake of lactobacilli or the Gram-negative bacteria P. lundensis have been thoroughly investigated amongst other things. Interestingly, it has been observed an activation of the specific cellular immune system in subjects receiving L. plantarum and indications of such in subjects receiving L. paracasei. Moreover, immunity-enhancing effects on the innate immune system, such as expansion of the NKT cell population and increased phagocytic activity were observed in subjects receiving different lactobacilli species. Intake of the Gram-negative bacteria P. lundensis had no effects, whatsoever, on the different immune parameters measured in this study.
An increasing problem in the west world are the autoimmune and autoimmune related diseases where the immune system of the human individual attacks itself by mistake and the individual can get very sick. The autoimmune diseases can affect connective tissues and many other parts of the body such as specific organs such as the skin, the nerves, the brain, lungs, kidneys and joints. An example of an autoimmune disease in the nerves and the brain is multiple sclerosis and on the skin an example is psoriasis. The autoimmune disease takes many different forms and there are also many treatments for them. The treatment depends on the type of the disease and the organ affected.
There is a need within the art to alleviate and treat the symptoms related to autoimmune diseases as well as provide a prophylactic treatment before the disease has developed. These issues are the subject matter of the present invention that will be apparent from the following.